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Fact Sheet Title Fact Sheet |
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European hake - Western Ionian Sea |
Merluccius merluccius - Western Ionian Sea (GSA 19) |
| Data Ownership | This document provided, maintained and owned by General Fisheries Commission for the Mediterranean (GFCM) , is part of GFCM Stock Status Reports data collection. |
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Monitoring Range Min2014. ident Block | ident Block | | Species List: | Species Ref: en - European hake, fr - Merlu européen, es - Merluza europea, ru - Мерлуза восточноатлантическая |
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| ident Block European hake - Western Ionian Sea Map tips - Click on to turn layers on and off
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gfcm Sub Area |
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19 | Western Ionian |
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Aq Res | Biological Stock: No Value: Sub-Regional Management unit: Yes Reference year: 2019
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Considered a management unit: An aquatic resource or fishery is declared as [Fishery] Management Unit if it is effectively the focus for the application of selected management methods and measures, within the broader framework of a management system. According to the FAO Glossary for Responsible Fishing, "a Fishery Management Unit (FMU) is a fishery or a portion of a fishery identified in a Fishery Management Plan (FMP) relevant to the FMP's management objectives." FMU's may be organised around fisheries biological, geographic, economic, technical, social or ecological dimensions , and the makeup and attribute of a fishery management unit depends mainly on the FMP's management objectives. |
Jurisdictional distribution: Jurisdictional qualifier (e.g. "shared", "shared - highly migratory") of the aquatic resource related with its spatial distribution. |
Environmental group: Classification of the aquatic resource according to the environmental group (e.g. pelagic invertebrate, or demersal fish) to which the species belong. |
Reference Year: The Reference Year is the last year considered in the stock assessment and/or fishery status. |
| | | | Aq Res State Trend In overexploitation, with relatively high biomass. [The GFCM methodology to provide stock status and management advice is described in the Appendix F of the Sixteenth Session of the Scientific Advisory Committee Report. See the Bibliography section.] Habitat Bio Climatic Zone: Temperate. Bottom Type: Soft bottom; Hard bottom. Depth Zone: Shelf (50 m - 200 m); Slope (200 m - 1000 m). Horizontal Dist: Neritic. Vertical Dist: Demersal/Benthic. Water Area Overview Spatial Scale: Sub-Regional Water Area Overview | Water Area Overview European hake - Western Ionian Sea
gfcm Sub Area | 19: Western Ionian |
| | | | Water Area Overview
| | | | Water Area Overview |
Water Area OverviewEuropean hake - Western Ionian Sea Aq Res Struct Biological Stock: No Stock assessment in the GFCM area of application is often conducted by management units, based on GSAs. This method does not ensure that the whole stock is assessed, since stocks may cover several different management units. In some cases, when there is scientific evidence of a stock spreading through different GSAs, as well as information on species from different GSAs, existing information is combined across GSAs. This is then defined as a “joint stock assessment of a shared stock”. The GFCM recommends that when scientific evidence of shared stocks exists, joint stock assessments should be attempted. A number of activities aimed at achieving a better definition of stock boundaries are currently being conducted at the GFCM level. [The State of Mediterranean and Black Sea Fisheries, 2016] Exploit Following the twenty-first SAC meeting (Egypt, June 2019), the benchmark stock assessment of European hake was carried out assuming the stock in the boundaries of the western Ionian Sea (GSA 19). European hake represents one of the most important demersal species in terms of landing and income in GSA 19, especially for longlines (20 percent of the European hake landing), gillnets and trammel nets (20 percent of the European hake landing), but also for trawlers (60 percent). Bio Assess Data Official landings are from DCF (2002-2019) and MEDITS survey indices (available from 1994, used from 2002 to 2019). The discard data are present from 2006 to 2019 with a gap in 2007 and 2008 (not mandatory). In the years 2004, 2005, 2007 and 2008 discard (weight and LFDs) was estimated according to the average discard ratio of the years 2006 and 2009. Biological information on von Bertalanffy growth parameters, maturity at length and length-weight relationship were derived within DCF (2002-2019). The natural mortality vector was estimated as an average of different methods (Gislason, Prodbiom revised version with unique solution, Chen and Watanabe, Brodziak (2011 and 2012), Lorenz and Gulland), consistently with the approach used in the benchmark assessment of European hake in the Adriatic Sea in 2019. Deterministic age slicing using DCF growth parameters was used to produce catch-at-age input for assessment. Assess Models Type: Age-structured a4a SCAA a4a (FLR, http://flr project.org/FLa4a) was performed at the European hake benchmark meeting (GFCM, 2020). The original survey catchability submodel used for the benchmark assessment resulted in high instability of the present assessment, in particular the original qmodel <- list(~factor(age), gcv = 0.5). It was replaced by a model assigning equal catchability at ages > 2, that was also considered at the benchmark (GFCM, 2020), having the similar goodness of fit diagnostics (gcv = 0.5) as the model accepted at the benchmark (qmodel <- list(~factor(age)). Fishing mortality and stock recruit submodels remain the same as used for the benchmark assessment. Results The results showed a decreasing pattern for fishing mortality that in 2018 was still well above the proxy of F0.1 (0.14), with a ratio of 2.32. The SSB shows some increase in the recent years, while the recruitment is stable. Sci Advice Reduce fishing mortality. STF available. Management Management unit: Yes Sources FAO. 2021. General Fisheries Commission for the Mediterranean. Report of the twenty-second session of the Scientific Advisory Committee on Fisheries, online, 22–25 June 2021. FAO Fisheries and Aquaculture Report No. 1347. Rome. https://www.fao.org/3/cb7622en/cb7622en.pdfReport of the Working Group on Stock Assessment of Demersal Species (WGSAD). Online, 18–23 January 2021. https://www.fao.org/gfcm/technical-meetings/detail/en/c/1412431/ Bibliography FAO. 2020. The State of Mediterranean and Black Sea Fisheries 2020. General Fisheries Commission for the Mediterranean. Rome. https://www.fao.org/3/cb2427en/cb2427en.pdfFAO. 2016. The State of Mediterranean and Black Sea Fisheries. General Fisheries Commission for the Mediterranean. Rome, Italy. https://www.fao.org/3/i5496e/i5496e.pdfFAO General Fisheries Commission for the Mediterranean/Commission générale des pêches pour la Méditerranée. Report of the sixteenth session of the Scientific Advisory Committee. St. Julian’s, Malta, 17–20 March 2014/Rapport de la seizième session du Comité scientifique consultatif. Saint Julien, Malte, Malte, 17-20 mars 2014. FAO Fisheries and Aquaculture Report/FAO Rapport sur les pêches et l’aquaculture. No. R1102. Rome. 2015. 250 pp. https://www.fao.org/3/i4381b/i4381b.pdf |
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